“The Stuff of Thought” explores the duality of human cognition: the modesty of its construction and the majesty of its constructive power. Pinker weaves this paradox from a series of opposing theories. Philosophical realists, for instance, think perception comes from reality. Idealists think it’s all in our heads. Pinker says it comes from reality but is organized and reorganized by the mind. That’s why you can look at the same thing in different ways.

Then there’s the clash between ancient and modern science. Aristotle thought projectiles continued through space because a force propelled them. He thought they eventually fell because Earth was their natural home. Modern science rejects both ideas. Pinker says Aristotle was right, not about projectiles but about how we understand them. We think in terms of force and purpose because our minds evolved in a biological world of force and purpose, not in an abstract world of vacuums and multiple gravities. Aristotle’s bad physics was actually good psychology.

How can we be sure the mind works this way? By studying its chief manifestation: language. Variations among verbs reflect our distinctions among physical processes. Nuances among nouns illustrate the alternate interpretations built into our most basic perceptions."